Follow-up
Follow-up aims at diagnosing metachronous lesion(s) or distant metastasis in the early stage. History taking and physical examination every 3 to 6 months for three years after surgery. CEA every 2 to 3 months for two or more years in patients who have had resection of liver metastasis. Colonoscopy looking for synchronise lesion(s) should be done shortly after surgery if preoperatively the scope cannot pass through the tumor; otherwise it should be done every 3 to 5 years. ASCO recommends against other routine follow-up tests such as Chest X-Ray, Ultrasound, CT, etc.
Prevention
Most colorectal cancers should be preventable, through increased surveillance, improved lifestyle, and, probably, the use of dietary chemopreventative agents.
Surveillance
Most colorectal cancer arise from adenomatous polyps. These lesions can be detected and removed during colonoscopy. Studies show this procedure would decrease by > 80% the risk of cancer death, provided it is started by the age of 50, and repeated every 5 or 10 years.
As per current guidelines under National Comprehensive Cancer Network at in average risk individuals with negative family history of and personal history negative for adenomas or Inflammatory Bowel diseases, flexible sigmoidoscopy every 5 years with fecal occult blood testing annually or double contrast barium enema are other options acceptable for screening rather than colonoscopy every 10 years (which is currently the Gold-Standard of care).
Lifestyle
The comparison of colorectal cancer incidence in various countries strongly suggests that sedentarity, overeating (i.e., high caloric intake), and perhaps a diet high in meat (red or processed) could increase the risk of colorectal cancer. In contrast, physical exercise, and eating plenty of fruits and vegetables would decrease cancer risk, probably because they contain protective phytochemicals. Accordingly, lifestyle changes could decrease the risk of colorectal cancer as much as 60-80%.
Chemoprevention
More than 200 agents, including the above cited phytochemicals, and other food components like calcium or folic acid (a B vitamin), and NSAIDs like aspirin, are able to decrease carcinogenesis in preclinical models: Some studies show full inhibition of carcinogen-induced tumours in the colon of rats. Other studies show strong inhibition of spontaneous intestinal polyps in mutated mice (Min mice). Chemoprevention clinical trials in human volunteers have shown smaller prevention, but few intervention studies have been completed today. Calcium, aspirin and celecoxib supplements, given for 3 to 5 years after the removal of a polyp, decreased the recurrence of polyps in volunteers (by 15-40%). The “chemoprevention database” 7 shows the results of all published scientific studies of chemopreventive agents, in people and in animals. Aspirin should not be taken routinely to prevent colorectal cancer, even in people with a family history of the disease, because the risk of bleeding and kidney failure from high dose aspirin (300mg or more) outweight the possible benefits.
For More Information
American Society of Colon and Rectal Surgeons
85 West Algonquin Road, Suite 550
Arlington Heights, IL 60005
Phone: 847–290–9184
Email:
[email protected]
Internet:
www.fascrs.org
National Cancer Institute
Cancer Information Service
Building 31, Room 10A16
31 Center Drive, MSC 2580
Bethesda, MD 20892–2580
Phone: 1–800–422–6237 or 301–496–6631
Internet:
www.nci.nih.gov